Remedy 1: Improve our understanding of the discrepancy between the calculated fitting uncertainty and the more realistically estimated total random error.

Primary gap remedy type: 
Research
Secondary gap remedy type: 
Technical
Proposed remedy description: 

The proposed action is to improve our understanding of the discrepancy between the calculated fitting uncertainty and the more realistically estimated total random error. This needs to be done, firstly, by evaluating all literature studies and other documentation available on this topic and, secondly, by using the results from the MAX-DOAS intercomparison campaign at Cabauw, the Netherlands, in September 2016, to provide more state-of-the-art data for further investigation specifically tailored to this issue. As part of GAIA-CLIM, we have developed a traceability chain for total column ozone measured by DOAS instruments and as part of this study we investigated, as a case study for two NDACC stations, the individual elements and their respective uncertainties leading up towards the DOAS fitting procedure and the uncertainties calculated within the fitting procedure. This is providing the first step for a quantitative investigation into the observed discrepancies which needs to be further extended e.g. with sensitivity studies of the uncertainties of the single components as well as an investigation of the potential of cancelling out of individual uncertainty components. The existing GAIA-CLIM work needs to be extended to be applicable across the full range of MAX-DOAS instrumentation in usage globally.

Relevance: 

This remedy is specific for measurements using UV-visible spectroscopic measurement techniques and it will address the existing gap by providing a better understanding on what causes the discrepancy between the calculated fitting uncertainty and the more realistically estimated total random uncertainty.

Measurable outcome of success: 

The success will be measured by how much we can improve our understanding of the difference between the individual uncertainty estimates versus the uncertainty provided by the data analysis fitting routines.

Expected viability for the outcome of success: 
  • Medium
Scale of work: 
  • Single institution
  • Consortium
Time bound to remedy: 
  • Less than 3 years
Indicative cost estimate (investment): 
  • Low cost (< 1 million)
Indicative cost estimate (exploitation): 
  • No
Potential actors: 
  • EU H2020 funding
  • Copernicus funding
  • National funding agencies
  • ESA, EUMETSAT or other space agency
  • Academia, individual research institutes